Olé
An excellent explanation. May I offer a small addendum as fas as the US is concerned.

After a BS from college, you are NOT entitled to design and "sign off" on new bridges. You will have to work for at LEAST two years at an engineering firm, then take a strenuous, full-day exam from New York State; and if you PASS it , THEN you will have a PE license. (Professional Engineer)

And you can now design and "sign off" on new structures, if someone will trust you with the job!